Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for Andromeda Galaxy: 12-24 (100), 12-25 (100), 12-26 (100), 12-27 (100), 12-28 (100) — by astronomy; check the weather when the night is within four days.

2037-12-14astronomy score per night — click a bar for that night2038-01-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-12-14 Mon	85	—	unknown	18:35–01:40 (good, 7.08 h)	89.7° 19:30	11.49	53%	48.2°
2037-12-15 Tue	71	—	unknown	18:35–01:10 (good, 6.58 h)	89.6° 19:25	11.49	62%	42.6°
2037-12-16 Wed	57	—	unknown	18:35–02:05 (marginal, 7.5 h)	89.6° 19:25	11.5	71%	39.2°
2037-12-17 Thu	45	—	unknown	18:35–01:50 (marginal, 7.25 h)	89.7° 19:20	11.5	79%	38.7°
2037-12-18 Fri	38	—	unknown	18:35–01:30 (marginal, 6.92 h)	89.8° 19:15	11.5	87%	41.3°
2037-12-19 Sat	37	—	unknown	18:35–01:15 (marginal, 6.67 h)	89.7° 19:10	11.51	93%	46.6°
2037-12-20 Sun	42	—	unknown	18:35–01:05 (marginal, 6.5 h)	89.5° 19:05	11.51	97%	54.0°
2037-12-21 Mon	52	—	unknown	18:35–18:45 (good, 0.17 h)	89.6° 19:05	11.51	100%	62.7°
2037-12-22 Tue	67	—	unknown	18:35–20:45 (good, 2.17 h)	89.8° 19:00	11.51	100%	72.5°
2037-12-23 Wed	77	—	unknown	18:40–22:30 (good, 3.83 h)	89.8° 18:55	11.5	98%	82.9°
2037-12-24 Thu	100	—	unknown	18:40–23:50 (good, 5.17 h)	89.6° 18:50	11.5	94%	93.6°
2037-12-25 Fri	100	—	unknown	18:40–00:30 (good, 5.83 h)	89.5° 18:50	11.5	87%	104.3°
2037-12-26 Sat	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.7° 18:45	11.49	78%	114.8°
2037-12-27 Sun	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.8° 18:40	11.49	68%	124.5°
2037-12-28 Mon	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.7° 18:35	11.48	57%	132.9°
2037-12-29 Tue	100	—	unknown	18:40–00:40 (good, 6.0 h)	89.6° 18:30	11.48	46%	139.0°
2037-12-30 Wed	100	—	unknown	18:40–00:35 (good, 5.92 h)	89.6° 18:30	11.47	35%	141.4°
2037-12-31 Thu	100	—	unknown	18:45–00:35 (good, 5.83 h)	89.7° 18:25	11.46	24%	139.6°
2038-01-01 Fri	100	—	unknown	18:45–00:30 (good, 5.75 h)	89.8° 18:20	11.45	15%	134.2°
2038-01-02 Sat	100	—	unknown	18:45–00:25 (good, 5.67 h)	89.7° 18:15	11.44	8%	126.2°
2038-01-03 Sun	100	—	unknown	18:45–00:20 (good, 5.58 h)	89.5° 18:10	11.43	3%	116.8°
2038-01-04 Mon	100	—	unknown	18:45–00:15 (good, 5.5 h)	89.6° 18:10	11.41	0%	106.8°
2038-01-05 Tue	100	—	unknown	18:45–00:15 (good, 5.5 h)	89.8° 18:05	11.4	0%	96.5°
2038-01-06 Wed	100	—	unknown	18:50–00:10 (good, 5.33 h)	89.8° 18:00	11.39	2%	86.3°
2038-01-07 Thu	100	—	unknown	18:50–00:05 (good, 5.25 h)	89.6° 17:55	11.37	6%	76.4°
2038-01-08 Fri	100	—	unknown	18:50–00:00 (good, 5.17 h)	89.5° 17:55	11.36	12%	67.0°
2038-01-09 Sat	96	—	unknown	18:50–00:00 (good, 5.17 h)	89.7° 17:50	11.34	18%	58.3°
2038-01-10 Sun	89	—	unknown	18:50–23:55 (good, 5.08 h)	89.8° 17:45	11.32	26%	50.6°
2038-01-11 Mon	82	—	unknown	18:50–23:50 (good, 5.0 h)	89.7° 17:40	11.3	35%	44.3°
2038-01-12 Tue	72	—	unknown	18:55–23:25 (good, 4.5 h)	89.6° 17:35	11.28	44%	40.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-12-14&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.